1. Field of the Invention
The present invention relates to an image capture apparatus and a method for controlling the same, and in particular to an image capture apparatus that can generate refocusable image data after having captured an image, and a method for controlling the same.
2. Description of the Related Art
In recent years, image capture apparatuses that record not only the integrated intensity of light incident on a pixel location but also the intensities of light incident on a pixel location in respective incident directions have been proposed, and are referred to as “light field cameras” and the like (Ren. Ng et al. “Light Field Photography with a Hand-Held Plenoptic Camera”, Stanford Tech Report CTSR 2005-02, Apr. 20, 2005). For example, by arranging a microlens array between a photographic lens and an image sensor so that an outgoing light flux of one microlens is received by a plurality of pixels of the image sensor, it is possible to obtain the intensities of light that was incident on the microlens from a different direction with each pixel.
A pixel signal (ray information) that was obtained in such a manner includes information on the intensities of the incident light in the respective directions at the position of the microlens. Therefore, a method that is called “Light Field Photography” can be applied to reconstruct an image in which a given imaging plane is focused (hereinafter, referred to as “refocused image”). Also, by adding together signals obtained with the plurality of pixels that have received the outgoing light flux of one microlens, it is possible to obtain a normal photographic image that has the same number of pixels as the number of microlenses. In the present specification, an image from which a refocused image can be reconstructed is referred to as a “light field image”.
In this method, information on one pixel of the reconstructed image (refocused image) is generated based on the information obtained with the plurality of pixels that have received the outgoing light flux of one microlens, and thus the pixel count of the reconstructed image is less than the total pixel count of the image sensor. The pieces of information obtained by the plurality of pixels are also combined to generate one pixel when generating a normal image which is not a light field image, and thus the image obtained will have a smaller pixel count than that of an image obtained by a normal camera using the same image sensor. That is to say, a conventional light field camera has a configuration just for photographing light field images, and normal images are situated as images that correspond to the position of a particular imaging plane of the light field image. Accordingly, performance in photographing a normal image, which is not refocusable, is inevitably deteriorated.
In order to solve such a problem, Japanese Patent Laid-Open No. 2010-102230 proposes a configuration of a lens-interchangeable camera in which a detachable microlens array is arranged at a joint part between an interchangeable lens and the camera. By employing a detachable microlens array, a light field image can be photographed only when the microlens array is attached, and a normal image that has the same pixel count as that of an image sensor at a maximum can be photographed, when the microlens array is detached.
In the conventional technology disclosed in Japanese Patent Laid-Open No. 2010-102230, an arrangement relationship between the microlens array and the image sensor is fixed, irrespective of the interchangeable lens or the image capture apparatus. Therefore, it is impossible to associate the microlenses with the pixels depending on differences in the size and the pixel count of image sensors included in image capture apparatuses.